"Fun" isn't a word normally associated with Eddie Vedder, a singer who has specialized in earnest sincerity ever since Pearl Jam's "Jeremy" blanketed MTV and modern rock radio in 1992. His guileless gravity served as Pearl Jam's lodestar in the ensuing decades, steering the band toward such weighty statements as Gigaton, a searing ecological warning the group delivered at the eve of their 30th anniversary. Earthling, the solo album Vedder released two years later -- it's his second, following the subdued Ukulele Songs by about 11 years -- feels as vigorous as Gigaton even as it sounds nothing at all like it. Vedder peppers Earthling with a few righteous rockers that are precisely in Pearl Jam's wheelhouse -- "Power of Right" helps kick off the record in a high gear -- but he spends most of the album playing the kind of vibrant, colorful rock Pearl Jam consciously avoids. Often, it seems as if Vedder is intent on reconnecting with the kind of rock that filled the airwaves in the days prior to grunge. "Invincible" is a stirring, openhearted anthem that conjures the ghost of prime Peter Gabriel, "The Dark" propels forward on an insistent widescreen rhythm reminiscent of late-'80s college rock, and "Fallout Today" is buoyed by thick layers of acoustic guitar. Vedder also invites a number of classic rockers to play on songs with explicit connections to their own past. "Mrs. Mills" is an unexpected bit of stately McCartneyesque pop anchored by Ringo Starr on drums, "Long Way" is a de facto homage to Full Moon Fever-era Tom Petty complete with Benmont Tench on keyboards, while "Picture" is a rollicking duet with Elton John, who also contributes barrelhouse piano. Vedder knows enough to throw a curveball on occasion, as when he has Stevie Wonder race to keep pace on "Try," a rocker invigorated by Stevie's harp. On a strictly musical basis, Earthling is the most varied project Eddie Vedder has ever released, and it's also his lightest album: there's a palpable joy to his free experiments here that's infectious, even fun. ~ Stephen Thomas Erlewine